The subject matter herein relates generally to compliant contacts and an electrical connector including the same that are configured to engage an electrical component, such as a circuit board.
Electrical connectors may be interconnected to circuit boards using compliant or press-fit contacts that form a mechanical and electrical coupling with the circuit board. For this purpose, the circuit boards include a plurality of thru-holes extending through a thickness of the circuit board. The thru-holes are typically “plated” to form plated thru-holes (PTHs) by covering inner surfaces that define the thru-holes with a conductive material, such as copper. Traces or other conductive elements that are connected to the conductive material of the PTHs form electrical pathways from the corresponding PTH to another portion of the circuit board.
To interconnect the circuit board and the electrical connector, the compliant contacts from the electrical connector are inserted into corresponding PTHs. Each compliant contact frictionally engages the conductive material within the PTH. For example, eye-of-needle (EON) contacts include a narrow beam of sheet metal that has a hole stamped therethrough. Outer edges of the EON contact have convex profiles proximate to the hole such that the outer edges arch or bow outwardly. A maximum diameter between the outer edges is slightly larger than a diameter of the PTH. When the EON contact is inserted into the PTH, the outer edges proximate to the hole engage the conductive material of the PTH.
However, conventional compliant contacts typically have a length that is more than sufficient for contacting an interior surface of the PTH. For example, manufacturers often desire for the compliant contacts to engage the PTH at a depth that is proximate to a first signal layer in the circuit board. After engaging the PTH at a first depth, the conventional compliant contacts generally continue to extend to a second depth. This additional length between the first and second depths (hereinafter referred to as a stub portion of the compliant contact) may cause unwanted noise with the surrounding PTH. To reduce the noise, the PTHs may be backdrilled to remove at least some of the plated conductive material that extends beyond the first depth. Backdrilling, however, can increase the cost of the circuit board.
In addition to the above, conventional compliant contacts are typically manufactured in a manner that is consistent with certain standards. For example, it is difficult to manufacture EON contacts in which the hole of the EON contact has a width that is less than a thickness of the stock material that forms the EON contact. As such, the ratio between the hole width and the stock thickness is typically 1.0 to 1.0. For certain configurations of a compliant contact, the ratio may be, at the very least, 0.85 to 1.0. Ratios less than this are typically not commercially reasonable, because the stock material is difficult to shape during manufacturing.
Accordingly, there is a need for a compliant contact that is capable of mechanically and electrically coupling to PTHs while having smaller dimensions than conventional compliant contacts.